Articles

Technical Article

Understanding and Controlling Parallel Query Processing in SQL Server

Data warehousing and general reporting applications tend to be CPU intensive because they need to read and process a large number of rows. To facilitate quick data processing for queries that touch a large amount of data, Microsoft SQL Server exploits the power of multiple logical processors to provide parallel query processing operations such as parallel scans. Through extensive testing, we have learned that, for most large queries that are executed in a parallel fashion, SQL Server can deliver linear or nearly linear response time speedup as the number of logical processors increases. However, some queries in high parallelism scenarios perform suboptimally. There are also some parallelism issues that can occur in a multi-user parallel query workload. This white paper describes parallel performance problems you might encounter when you run such queries and workloads, and it explains why these issues occur. In addition, it presents how data warehouse developers can detect these issues, and how they can work around them or mitigate them.

2010-12-10

4,645 reads

Blogs

AI: Blog a Day – Day 6: Embeddings – How AI Understands

By

Continuing from Day 5 where we covered notebooks, HuggingFace and fine tuning AI now...

The Book of Redgate: Mistakes

By

This is kind of a funny page to look at. The next page has...

ADF Pipeline Debugging Fails with BadRequest – The Sequel

By

A while ago I blogged about a use case where a pipeline fails during...

Read the latest Blogs

Forums

Dynamic Unpivot

By pietlinden

I have a table I didn't design that has tons of repeating groups in...

Writing as an Art and a Job

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Writing as an Art and...

String Similarity II

By Steve Jones - SSC Editor

Comments posted to this topic are about the item String Similarity II

Visit the forum

Question of the Day

String Similarity II

What is the range for the result from the EDIT_DISTANCE_SIMILARITY() function in SQL Server 2025?

See possible answers